Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
thanh de » hanh de, thanh ve, thanh do
va thanh » gia thanh, ban thanh, va tinh
mai khoa » tai khoa, may khoa, dai khoa
hieu va » lieu va, hieu qua
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
cua tuc » cua duc, cua tu, cua thuoc
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
de cua » le cua, te cua, dieu cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach v nang ((mai hoi) or (mai khoa)). ((hieu van) OR (hieu va)) pham duc va thanh de cua tuc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach v nang ((mai hoi) OR (mai khoa)). ((hieu van) OR (hieu va)) pham duc va thanh de cua tuc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang ((mai hoi) or (mai khoa)). ((hieu van) OR (hieu va)) pham duc va thanh de cua tuc".
• Adding a wildcard symbol may retrieve word variants: su sach v nang ((mai hoi) or (mai khoa)). ((hieu van) OR (hieu va)) pham duc va thanh de cua tuc*.